Suspension mounting assembly for automatic washer

ABSTRACT

A vertical axis washing machine having a washing receptacle and drive means supported by three suspension element assemblies. Due to vertical movement of the suspension assemblies with the addition or removal of washing liquid from the washing receptacle, the suspension element assemblies provide a damped spring system during the washing cycle and an undamped spring system during the extraction cycle. A vertical attitude of the washing receptacle is attained by providing the suspension element assemblies with differing spring rates by varying the number of free coils of a spring in each of the suspension element assemblies.

United States Patent 1191 Czech et al.

1111 3,854,308 1451 Dec, 17,1974

[ SUSPENSION MOUNTING ASSEMBLY FOR AUTOMATIC WASHER [75] Inventors:James I. Czech, Stevensville; Roy C.

Oakley, .lr., Coloma, both of Mich.

[73] Assignee: Whirlpool Corporation, Benton Harbor, Mich.

22 Filed: Jan. 23, 1973 211 Appl. No.: 325,983

[52] US. Cl 68/233, 68/235, 210/364, 248/20, 248/350, 248/358 AA,267/178 [51] Int. Cl. D06! 37/24 [58] Field of Search 68/231, 23.3,23.5; 210/364, 1.44; 248/20, 2l, 350, 358 AA; 267/178 [56] ReferencesCited UNITED STATES PATENTS 12/1945 Geldhof et al. 68/233 11/1966Douglas et al.

8/1971 Conrath et 81 68/233 x FOREIGN PATENTS OR APPLICATIONS 439.6239/1948 Italy 248/35o Primary ExaminerHarvey C. Hornsby AssistantExaminerPhilip R. Coe

Attorney, Agent, or Firml'l ill, Gross, Simpson, Van Santen, Steadman,Chiara & Simpson ABSTRACT A vertical axis washing machine having awashing receptacle and drive means supported by three suspension elementassemblies. Due to vertical movement of the suspension assemblies withthe addition or removal of washing liquid from the washing receptacle,the suspension element assemblies provide a damped spring system duringthe washing cycle and an undamped spring system during the extractioncycle. A vertical attitude of the washing receptacle is attained byproviding the suspension element assemblies with differing springratesby varying the number of free coils of a spring in each of thesuspension element assemblies.

10 Claims, 8 Drawing Figures PATENTEL LEE 1 "(1974 saw 1 or 2 PATENI DEC1 H974 sum 20F 2 w w w 0 o 0 o 0 0 3 33 33 3 i 5, i fl O a 2 5 Y O A 255 3 5 6 a 5 3 5/5 H 5 7 w 55 9 Z SUSPENSION MOUNTING ASSEMBLY FORAUTOMATIC WASHER BACKGROUND OF THE INVENTION washing, rinsing and dryingmachines for home use has been an area of continuing development.Excessive vibrations usually occur when there is a non-uniformdistribution of clothes in the rotating clothes container or basket as,the same spins rapidly to centrifuge excess water from the clothes.While a high rate of spin is desirable during the centrifugingoperation, the maximum rate of spin is limited by the capabilities ofthe tub suspension system to isolate the machine cabinet from thevibrations or oscillatory motion caused by the unbalanced load. Acomplex suspension system may permit a high rate of spin, however, inorder to maintain the cost of the laundry appliance within the reachofmostconsumers, the suspension system should also be com-' pact,inexpensive and easily assembled. The use of ex- FIG. 3 is a topschematic view of the automatic washer showing the positions of thethree suspension elements and the center of gravity of the machine;

FIGS. 4, 5 and 6 are sectional views of the three suspension elements;

FIG. 7 is a side view of the lower spring mount of the suspensionelement shown in FIG. 4; and

FIG. 8 is atop view of thelower spring mount of FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment, asillustrated in the drawings, the automatic washer 7 has a suspensionsystem comprising three assemblies or elements, 25, 26 and 27. Supportedby these three elements is a conventional clothes receptacle assembly 8including a drive means. The clothes receptacle assembly, comprises abase plate 20, attached to the top of which is a tub 12 i r with arotatable basket 13 mounted inside for receiving clothes to be washed.An agitator 14 is provided inside tension springs and mechanisms forproviding both SUMMARY OF THE INVENTION A washing receptacle suspensionsystem is provided to stabilize the receptacle during a washingoperation,

prevent excessive vibration transfer to the cabinet during acentrifuging operation, and to maintain a vertical attitude of thewashing receptacle in the unloaded condition. v v

The suspension system has a plurality of essentially I identical helicalsprings vertically oriented with each having a plurality of coils.Uppermounting means are provided for mounting each of the springs to therecep-' tacle at one end and lower mounting means are provided formounting each of the springs to a base at the other end. The lowermounting means have a surface defining a cylindrically shaped member andhave a groove in the surface defining a helix'on the cylindricallyshaped member of sufficient length to receive at least one of the springcoilsfFirst, second and third lower spring mounts are provided, eachhaving a different length of helix, for receiving a differing number ofspring coils.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectioned view of theautomatic washer"- showing the suspension of the invention in theundamped mode;

FIG. 2 is a sectioned view of the automatic washer showing thesuspension of the damped mode;

the basket 13 to agitate a clothes load during the washing cycle. Thedrive means for the agitator l4 and basket 13 is provided by a motor 15and a transmission 16. Water enters the tub 12 through a solenoidoperated valve 3 and water inlet 4 from an appropriate source .(notshown). A pump 28 is provided to pump the washing liquid from the tub 12through an appropriate plumbing system (not shown) to a drain (notshown). A conventional timer 17 is provided to control the variouscycles of the automatic washer.

As illustrated in FIG. 4 by suspension element 26, an element consistsof a spring 30, and upper and lower resilient spring mounts 31 and 32,respectively-The mounts are held in place by respective screws 5 and 6as shown in FIG. 2. The upper spring mount 31 is attached to a support22 of base plate 20. The lower spring mount 32 is attached to thecabinet base 18. At the point of attachment of the lower spring mount 32to the cabinet base, a protrusion 19 is provided to facilitate properpositioning of the mount on the base. This suspension element mountingand construction provides for the unique features of the suspensionsystem of the automatic washer as is hereafterexplained.

The washer has conventional cycles of agitation, pumpout, and extractionor centrifuging. During operation of the automatic laundry appliance orwashing machine 7, the tub 12 is first filled with water or otherlaundry solution through inlet 4 and the agitator 14 is oscillated viathe transmission unit 16 and the motor 15. After completion of thatoperation,'thewater is drained from the tub l2'by pump 28 and the basket13 is thereafter rotated at a high speed to extract or centrifuge thewater from the clothes contained in the basket. In the event the clothesare non-uniformly located or distributed within the basket during theextraction op eration, the basket, tub, and base will together executean oscillatory motion, which, if transmitted to the cabinet, may causean undesirable and excessive vibration. The suspension system of thepresent invention is designed through the use of springs having a lowspring rate (lb. force applied/in. deflection) to isolate the rotatingand oscillating parts from the cabinet 10 and cabinet base 18 during theextraction cycle, thereby preventing vibration transfer. Because of thelow spring rate of the suspension springs, when the wateris added to thetub 12 for the agitation cycle, the weight of the water added causes thereceptacle assembly 8 to move down against the upward force of thesprings until the upper and lower spring mounts bottom against eachother. As illustrated by assembly 26 in FIG. 2, upper spring mount 31 isbottomed against the hollow cylindrical portion 33 of the lower springmount 32. During the pump out cycle, water is pumped from the tub 12 bythe pump 28 to an appropriate drain. The upward force of the springs isthen greater than the weight of the receptacle assembly 8 and theassembly moves upward as shown in FIG. 1. In this portion of the pumpout cycle and in the extraction cycle, as illustrated by assembly 26,the upper mount 31 and the cylindrical portion 33 of the lower mount 32are no longer in contact, and the receptacle assembly is suspended onlyon the springs.

It is therefore contemplated by thepresent invention to allow thesuspension system to provide large damping of the forces created duringthe agitation cycle and essentially no damping of forces during the spincycle. These characteristics are desirable because during the washingcycle large forces are created by the oscillatory motion of the agitatoragainst the clothes and water in the tub and a stable tub support isneeded to prevent movement of the tub which might cause damage to thecabinet or which might cause the liquid in the tub to splash out the topopening 9 in the tub and run down onto the electrical components such asthe motor 15 and cause electrical shorting. The stable base during theagitate cycle is provided in the instant invention by contact of theupper and lower spring mounts when water is added to the tub. However,during the extraction cycle it is best to provide no damping and asuspension with a low spring rate such that if an unbalance occurs inthe basket due to an off balance load the forces created by the offbalance will be most effectively isolated. This is due to the fact thatsuspension systems with low damping rates provide for lower transmissionof forces above the system critical speed than do systems with largedamping. Also, systems with a lowspring rate have a lower critical speedso that during acceleration of the basket at the start of the extractioncycle the critical speed is quickly passed through. The low damping andlow spring rate of the instant suspension system are provided by theseparation of the upper and'lower spring mounts when water is drainedfrom the tub. Because of the low spring rates utilized.

force be created by an unbalanced load during acceleration of the basketthrough critical speed during the extraction cycle. The lower springmount 32 is provided with a hollow cylindrical extension 33. The outerdiam- I The suspension element assemblies further provide for a verticalattitude of the receptacle assembly 8 when not loaded with clothes andwashing liquid. Because the center of gravity of the receptacle assemblyis not in the center of the receptacle assembly, due to the off centerplacement of motor 15, the suspension assemblies must provide a means ofattaining a vertical attitude of the receptacle. With the threesuspension elements 25, 26 and 27 equally spaced from the center of themachine and 120 apart, as shown in FIG. 3, it is required that the threesuspension elements have differing spring rates in order to maintain thevertical attitude of the tub and agitator when the tub is not loadedwith clothes and washing liquid. The three elements 25, 26 and 27, shownin FIGS. 4, 5 and 6, are of differing spring rates to provide for avertical attitude of the tub assembly so that when the weight of thereceptacle assembly is applied, each element will deflect the sameamount even though each is supporting a different weight. Each elementcomprises a spring, an upper resilient spring mount, and alowerresilient spring mount. The three springs 30, 40 and 50 are essentiallyidentical, each having the same free length, diameter of wire and numberof coils. Each of the three upper spring mounts 31, 41 and 51 are alsoessentially identical each being generally cylindrical and havinghelical grooves 34, 44 and 54 on their cylindrical surface to'receive35, 45 and 55, respectively, on their cylindrical surface and extensions33', 43 and 53 respectively for the purpose previously discussed. Metalinserts 36, 46 and 56 are provided in the lower mounts 35, 45 and 55respectively to receive bolts or screws tosecure the mounts. to thecabinet base 18. The spiral grooves provided in the lower spring mountsare of differing lengths to provide for receiving different numbers ofcoils of the respective springs. As shown in FIG. 4, lower spring mount32 has a groove 35 of sufficient length to receive approximately 2.5coils,'30a, 30b and one half of 300, Y

of spring 30. In FIG. 5, lower spring mount 42 has a groove ofsufficient length to receive approximately 3.5

coils, 40a, 40b, 40c and one half of 40d, of spring 40. In FIG. 6, lowerspring mount 52 is provided with a spiral groove of sufficient length toreceive approximately 4.25 coils, 50a, 50b, 50c, 50d and one quarter of50e, of spring 50.

Being representative of all the lower spring mounts 32, 42 and 52, mount32 is shown in FIGS. 7 and 8. The

mount is generally cylindrically shaped and has a large diameter lip 38cat the lower end 38a. Hollow cylindrical extension 33 protrudes from theupper end 38b.

The cylindrical surface of mount 32 has a helical groove 35 extendingfrom end 38b to end 38a for receiving approximately 2.5 coils .of spring30. At end 38a of the mount a protrusion 39 is provided to form alocating stop for abutting the spring 30 when it is received in thegroove.

As previously stated, each of the suspension elements has a differentspring rate in order to maintain a vertical attitude of the tub andagitator. The differing spring rates of the elements are realized eventhough the unassembled springs are essentially. the same because thelower spring mounts capture a different number of coils of each spring.This varies the number of free coils of each spring and because thespring constant of a spring is inversely proportional to the number offree coils, the spring constant is different for each of the assembliesshown. Referring to FIGS. 4, 5 and 6, it can be seen that the upperspring mounts 31, 41 and 51 in each of the elements 26, 25 and 27capture approximately 2.5 of the 14.5 coils of the spring shown. Element26 has coils 30a through one half of 30p, and upper mount 31 capturescoils 30m, 30n and one half of 30p. Element 25 has coils 40a through onehalf of 40p and upper mount 41 captures coils 40m, 40m and one half of40p. Element 27 has coils 50a through one half of 50p and upper mount 41captures coils 50m, 50h and one half of 50p. The lower spring mount inFIG. 4 captures approximately 2.5 coils of the spring leaving 9.5 activespring coils, the upper half of 300 through 30 L, in the element of FIG.4. The lower spring mount in FIG. 5 captures approximately 3.5 coils ofthe spring leaving 8.5 active coils, the upper half of 40d through 40L,in the spring of the element of FIG. 5. The lower spring mount in FIG. 6captures approximately 4.25 coils of the spring leaving 7.75 activecoils, the upper three quarters of 50e through 50L, in the spring in theelement 27 of FIG. 6. Thus, it can be seen that even though the springs30, 40 and 50 in the respective elements 26, 25 and 27 are essentiallythe same the spring constants of the elements differ, element 27 havingthe highest spring rate, and element 26 having the lowest spring rate. I

Although the arrangement shown is preferred, the same results ofdiffering spring constants for the element could be accomplished byvarying the length of groove in the upper element instead of the lowerelement or by a combination of varying groove lengths in upper and lowerelement's.

Although minor modifications might be suggested by those versed in theart, it should be understood that I i wish to embody within the scope'of the patent warranted hereon all such modifications as reasonably andproperly'come within the scope of my contribution to the art. v

Having described the invention, the embodiments of the invention inwhich an exclusive property or privilege is claimed are defined asfollows:

1. In a vertical axis automatic washing machine having a cabinet, acabinet base, and a receptacle assembly within said cabinet, asuspension means for suspending said receptacle assembly above saidbase, said suspension means comprising:

a plurality of essentially identical, vertically oriented helicalsprings each having the same mumber of coils;

a plurality of mounting members, one for connecting each of said springsto said receptacle assembly at one end portion of each of said springs,and also for connecting each of said springs to said base at theopposite end portion of each of said springs, said mounting members eachhaving a generally cylindrically shaped surface with ahelical groove insaid surface of sufficient length to receive engagingly a given numberof said spring coils of the one of said springs associated therewith,one of said mounting members as so connected to one end of one of said 6springs having a longer such groove than at least one other of saidmounting members as connected to one end of at least one otherrespective one of said springs, whereby said one spring has a differ-'ent number of free coils and a different spring rate than said at leastone other respective one of said springs;

each of said mounting members which so connects its associated onespring to said base being provided with an extension means projectinginteriorly in said associated one spring in radially spaced, adjacentrelationship to certain of said spring coils whereby, when a relativelylarge force tends to move said receptacle assembly horizontally, saidspring coils of said associated one spring can contact said extensionmeans.

2. A vertical axis washingv machine according to claim 1 wherein saidmounting members connecting respective ones of said springs to saidreceptacle assembly each have the same respective groove length and saidone mounting member and said at least one other mounting member connecttheir respective associated spring members to said base.

3. A vertical axis washing machine according to claim 1 wherein saidmounting members connecting respective ones of said springs to saidreceptacle assembly each have the same respective groove length and saidmounting members connecting respective ones of said springs to said baseeach have a different respective groove length.

4. A- vertical axis washing machine according to claim 1 wherein saidmounting members connecting respective ones of said springs to saidreceptacle assembly and said mountingmembers connecting respective onesof said springs to said base are resilient and have metal insertsfor-receiving screws thereinto to secure said mounting members,respectively, to said receptacle assembly to said base.

5. Ina vertical axis automatic washer having a cabinet, a cabinet base,a receptacle assembly within said cabinet, said receptacle assemblyincluding a tub, a

basket within said tub mounted for spinning movement about a centeraxis, and a drive mechanism for said basket, saidreceptacle assemblyhaving a center of gravity displaced from said center axis, and asuspension system for suspending said receptacle assembly above saidcabinet base, said suspension system comprising: v

a plurality of suspension assemblies each having a given spring rate,each of said suspension assemblies including in combination: anessentially identical helical spring; an upper mounting means forconnecting said spring to said receptacle assembly; a lower mountingmeans for connecting said spring to said cabinet base; I said upper andsaid lowerspring mounting means providing at least one of saidsuspension assemblies with a given spring rate different from the givenspring rates of the other of said assemblies; said suspension systemcompensates for said ,center of gravity being not on said center axis tomaintain said center axis in a substantially vertical attitude;

said vertical axis automatic washer further being provided with a waterinlet means within said cabinet for filling said tub with water toprovide a water level within said tub, and further with an extensionmeans on each of said lower mounting means for insertion into saidspring of each of said suspension assemblies, said extension means beingspaced at a distance from said upper mounting means in each of therespective said suspension assemblies when said tub is filled with waterbelow said water level, and being movable to contact said upper mountingmeans in each of such respective received determines said given springrate of each of i said assemblies.

7. A vertical axis automatic washer according to claim 6 wherein saidmounting means are resilient.

8, In a vertical axis automatic washer having a cabinet, a cabinet base,a receptacle assembly within said cabinet, said receptacle assemblyincluding a tub, a

basket within said tub mounted for spinning movement about a centeraxis, and a drive mechanism for said basket, said receptacle assemblyhaving a center of gravity an essentially identical helical spring; anupper mounting means for connecting said spring to said receptaclemounting assembly; and

a lower mounting means for connecting said spring to said cabinet base;said vertical axis washer fur-.

ther having a water inlet means within said cabinet for filling said tubwith water to provide a water level within said tub, and an extensionmeans on each of said lower mounting means for insertion into saidspring of each of said suspensionassemblies, said extension means beingspaced at a distance from said upper mounting means in each of therespective suspension assemblieswhen said tub is filled with waterbelow' said water level, and-being'movable to contact said uppermounting means in each of such respective suspension assemblies whensaid tub is filled with water to said water level to provide support forsaid tub.

9. The vertical axis automatic washer of claim 8 1 wherein said upperand' said lower mounting means is adapted to provide at least'o ne ofsaid suspension assemblies with a given spring rate which is differentfrom the given spring rates of the other of said suspension 215-semblies whereby said suspension system compensates displaced from saidcenter axis, and a suspension sys-- tem for suspending said receptacleassembly above said cabinet-base, said suspension assembly comprising:-

a plurality of suspension assemblies each having a given spring rate,each of said suspension assemblies including in combination:

for said center of gravity being so displaced from said center axis tomaintain' s'aid center axisin a substantially vertical attitude. I i

10. The've'rtical axis automatic washer of claim 5 wherein saidmountingfmeans are resilient.

1. In a vertical axis automatic washing machine having a cabinet, acabinet base, and a receptacle assembly within said cabinet, asuspension means for suspending said receptacle assembly above saidbase, said suspension means comprising: a plurality of essentiallyidentical, vertically oriented helical springs each having the samemumber of coils; a plurality of mounting members, one for connectingeach of said springs to said receptacle assembly at one end portion ofeach of said springs, and also for connecting each of said springs tosaid base at the opposite end portion of each of said springs, saidmounting members each having a generally cylindrically shaped surfacewith a helical groove in said surface of sufficient length to receiveengagingly a given number of said spring coils of the one of saidsprings associated therewith, one of said mounting members as soconnected to one end of one of said springs having a longer such groovethan at least one other of said mounting members as connected to one endof at least one other respective one of said springs, whereby said onespring has a different number of free coils and a different spring ratethan said at least one other respective one of said springs; each ofsaid mounting members which so connects its associated one spring tosaid base being provided with an extension means projecting interiorlyin said associated one spring in radially spaced, adjacent relationshipto certain of said spring coils whereby, when a relatively large forcetends to move said receptacle assembly horizontally, said spring coilsof said associated one spring can contact said extension means.
 2. Avertical axis washing machine according to claim 1 wherein said mountingmembers connecting respective ones of said springs to said receptacleassembly each have the same respective groove length and said onemounting member and said at least one other mounting member connecttheir respective associated spring members to said base.
 3. A verticalaxis washing machine according to claim 1 wherein said mounting membersconnecting respective ones of said springs to said receptacle assemblyeach have the same respective groove length and said mounting membersconnecting respective ones of said springs to said base each have adifferent respective groove length.
 4. A vertical axis washing machineaccording to claim 1 wherein said mounting members connecting respectiveones of said springs to said receptacle assembly and said mountingmembers connecting respective ones of said springs to said base areresilient and have metal inserts for receiving screws thereinto tosecure said mounting members, respectively, to said receptacle assemblyto said base.
 5. In a vertical axis automatic washer having a cabinet, acabinet base, a receptacle assembly within said cabinet, said receptacleassembly including a tub, a basket within said tub mounted for spinningmovement about a center axis, and a drive mechanism for said basket,said receptacle assembly having a center of gravity displaced from saidcenter axis, and a suspension system for suspending said receptacleassembly above said cabinet base, said suspension system comprising: aplurality of suspension assemblies each having a given spring rate, eachof said suspension assemblies including in combination: an essentiallyidentical helical spring; an upper mounting means for connecting saidspring to said receptacle assembly; a lower mounting means forconnecting said spring to said cabinet base; said upper and said lowerspring mounting means providing at least one of said suspensionassemblies with a given spring rate different from the given springrates of the other of said assemblies; said suspension systemcompensates for said center of gravity being not on said center axis tomaintain said center axis in a substantially vertical attitude; saidvertical axis automatic washer further being provided with a water inletmeans within said cabinet for filling said tub with water to provide awater level within said tub, and further with an extension means on eachof said lower mounting means for insertion into said spring of each ofsaid suspension assemblies, said extension means being spaced at adistance from said upper mounting means in each of the respective saidsuspension assemblies when said tub is filled with water below saidwater level, and being movable to contact said upper mounting means ineach of such respective suspension assemblies when said tub is filledwith water to said water level to provide support for said tube.
 6. Avertical axis automatic washer according to claim 5 wherein said givenspring rate is dependent on the number of free coils of said helicalsprings and said upper and lower spring mounting means comprise memberseach having a cylindrically shaped surface provided with helical groovesto receive engagingly a number of coils of said springs and said numberof coils received determines said given spring rate of each of saidassemblies.
 7. A vertical axis automatic washer according to claim 6wherein said mounting means are resilient.
 8. In a vertical axisautomatic washer having a cabinet, a cabinet base, a receptacle assemblywithin said cabinet, said receptacle assembly including a tub, a basketwithin said tub mounted for spinning movement about a center axis, and adrive mechanism for said basket, said receptacle assembly having acenter of gravity displaced from said center axis, and a suspensionsystem for suspending said receptacle assembly above said cabinet base,said suspension assembly comprising: a plurality of suspensionassemblies each having a given spring rate, each of said suspensionassemblies including in combination: an essentially identical helicalspring; an upper mounting means for connecting said spring to saidreceptacle mounting assembly; and a lower mounting means for connectingsaid spring to said cabinet base; said vertical axis washer furtherhaving a water inlet means within said cabinet for filling said tub withwater to provide a water level within said tub, and an extension meanson each of said lower mounting means for insertion into said spring ofeach of said suspension assemblies, said extension means being spaced ata distance from said upper mounting means in each of the respectivesuspension assemblies when said tub is filled with water below saidwater level, and being movable to contact said upper mounting means ineach of such respective suspension assemblies when said tub is filledwith water to said water level to provide support for said tub.
 9. Thevertical axis automatic washer of claim 8 wherein said upper and saidlower mounting means is adapted to provide at least one of saidsuspension assemblies with a given spring rate which is different fromthe given spring rates of the other of said suspension assemblieswhereby said suspension system compensates for said center of gravitybeing so displaced from said center axis to maintain said center axis ina substantially vertical attitude.
 10. The vertical axis automaticwasher of claim 5 wherein said mounting means are resilient.